With age, a large percentage of the population develops atherosclerotic arterial obstructions resulting in diminished blood circulation. The disturbance to blood flow that these obstructions cause may induce blood clots which further diminish or block the blood flow. When this process occurs in the coronary arteries it is referred to as a heart attack. Presently such obstructions are circumvented by surgically grafting a bypass or they are treated by a catheter equipped with a balloon which is inserted through the arterial system, over a flexible guide wire assembly, into the obstruction and then inflated to expand the obstruction's lumen (angioplasty). Some of the problems with angioplasty are injury to the arterial wall, creation of a rough lumen, and in a number of the cases it is ineffective. Further, angioplasty does not remove the obstruction material out of the arterial system, therefore in a case of a heart attack, immediate angioplasty carries the risk of dislodging the blood clot and allowing it to move down stream creating additional blockages.
An objective of the present invention is to provide an atherectomy system having a flexible guide wire assembly which rotatably and slidably supports a flexible rotary catheter having a tubular blade at its distal end to cut and separate the obstruction from the artery and create a smooth lumen through it without cracking the arterial wall. The flexible guide wire assembly preferably defines voids for containing obstruction material.
Another objective is teach a design of an atherectomy catheter that lends itself to be produced in a range of diameters, down to about 1 mm (millimeter), and a length sufficient to reach remote arteries.
Another objective is teach a design of an atherectomy catheter that, in operation, would utilize existing skills of the medical staff such as gaining access to the patient vascular system and the manipulation of guide wires and catheters through it. These and other objectives of the invention will become apparent from the following discussion and the accompanying drawings.